The First Month of Lactation - Minimising Negative Energy Balance

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The management of the first month of lactation beyond the colostrum period very critical for herd level performance. Most cows will spend this period in negative energy balance (NEB). This is why providing consistently high feed quality is imperative. What we have learnt from cow collars is that farms that are having low rates of pre-mate heats four weeks before planned start of mating will still be low just before mating.

Cows in significant negative energy balance may develop clinical or sub-clinical ketosis. Fats mobilised (NEFAs) will also damage and therefore reduce the fertility of developing eggs on the ovaries.

Cows which are well fed/have a good appetite in the first month of lactation will lose less weight and have better mating performance. Consider the following:

  • Optimal pre-graze covers of 3,000 to 3,400 kgDM/ha in the first round will ensure good quality and easy harvest for the cow, while maintaining a residual at 1,550-1,600kgDM/ha.

  • Know what your daily cow requirement is and calculate your allocation every day - where feed deficits exist on any given day fill it with appropriate supplement.

  • If the herd or part of the herd is skinny and there are large feed deficits ahead, production may be best sacrificed by OAD milking for up to 3 weeks to maintain BCS leading into mating.

  • Use monensin (Rumenox), to increase feed conversion efficiency, by driving propionate production. Clinical trials show boost in milk protein production and far less BCS loss. Use strategically from calving up until end of mating.

  • Internal parasites – the biggest impact these have is on appetite suppression. Almost all farms will have high levels of over-wintered larvae this year. Aim to drench your herd by early/mid-September.

  • Vitamin B12 – is a requirement for energy extraction. Deficient cows will lose appetite. We see B12 levels drop at the same time as spring grass goes lush. This is partly due to rapid transit times through the gut impeding B12 absorption. Rule of thumb “when faeces start becoming loose look to give Vit B12”.